but not on most (if not all) of the other titles on the db.
Is it a special case because it was written as Ninkū on the cover (but also with kanji, so why not used Ninkuu like for other titles) ?
If this is the reason, why not Shienryu (written on the cover) instead of Shienryuu http://redump.org/disc/5054/ ?
I am for Ninkuu.
Something to check.